A wide-area nodal frequency estimation and tracking approach

Synchronization of the nodal frequencies at a nominal frequency value throughout the network is essential for ensuring the reliable operation of the entire power system. This synchronization is achieved by maintaining a near real-time generation load balance. A large disturbance in this balance results in frequency deviations in time and space. Since significant frequency deviations can lead to load shedding, operating instability, and even blackouts, system operators use a combination of control actions to restore the system frequency very close to its nominal level. The effectiveness of these control actions, however, will depend on the accuracy with which the system-wide frequency is measured. A novel approach for directly tracking the frequency at each node of an electric power system is proposed in this paper. This approach is based on a tracking state estimation and considers two different methodologies, according to the existing time frame between estimations. Lastly, case studies are presented to evaluate the proposal's effectiveness in estimating nodal frequencies and directly observing interarea oscillations from the state estimation results.